WATCH: Kim and Kanye to add mega pool to their Hidden Hills mansion

Kim Kardashian West and Kanye West want to build a huge outdoor swimming pool at their mansion.

The showbiz couple - who have kids; North, five, Saint, two, and Chicago, seven months, together - have been granted planning permission by the city of Hidden Hills, California to install a 20ft (6m) by 60ft-long (18m) in-ground pool at their roughly $60-million estate, according to documents obtained by TMZ.

It's been estimated that the construction work will cost a little over $50 000 (about R660 000) but it's thought they will spend more than that to ensure all the water is running sufficiently and is clean.

The permit was reportedly granted last month so there's a chance they've already started work on the pool, meaning there's a possibility that it will be ready before the end of this summer.

And to ensure no one gains access to the site, the pair also sought approval to build a new guard around the outside - valued at almost $12 000 - as they want the upmost privacy and security.

Kim and Kanye have done everything they can to increase the protection of this mansion after the 37-year-old reality TV star was held at gunpoint in her hotel room in Paris, France, back in 2016 and had a large quantity of her jewellery taken by robbers.

She said previously: "I just have anxiety, are you sure it's safe here? Ever since Paris I just go through this worst case scenario thing in my head. "I think for my own piece of mind I'm going to fly out like four more security - just to like stay outside my room when I'm sleeping, I know it sounds crazy but I just can't sleep at night."

Her anxiety was so bad last year that she refused to leave her home and go out with Kanye.

She explained: "I have such anxiety just going places. I just don't want to be in the mix like I used to ... Kanye's like, 'Let's go out to dinner' and I'm like, 'I can't, I can't enjoy myself.'

"I think I have to get out of my shell but I don't want to, I like living this more chill life. I've become socially awkward for sure ... I am so afraid of everything, anxiety, pressure."